The Ripper Miner--an All-purpose Excavation Method.
Paper in Mining Tech Economics and Policy 1990 :509-524
The U.S. Bureau of Mines has developed an extraction system called the ripper miner. This concept uses a single, wide bit that attacks the rock at a shallow angle and slow speed. Research has demonstrated that the system is capable of excavation rates exceeding those possible with conventional drill-blast and can effectively cut rock too hard for roadheaders or continuous mining machines. The soft-rock version has the additional advantages of low bit wear and low dust generation. A single ripper miner can perform the functions of a continuous mining machine, a roadheader excavator, and a tunnel-boring machine. This paper presents the results of full-scale laboratory tests performed in both soft and hard rocks using two different cutterheads. It also includes a comparison of the ripper miner to systems currently used from the standpoint of energy efficiencies and operating costs.
Paper in Mining Tech., Economics and Policy 1990. Am. Min. Congr., PP. 509-524